Electronic device and control method for the same

Abstract

An electronic device comprises a first converter circuit converting an input voltage from a first or second power source to a first output voltage being 1/n of the input voltage (n>=2); a second converter circuit converting the input voltage from the second power source to a second output voltage; and a third converter circuit converting a higher one of the first and second output voltages to a third output voltage to be supplied to a load. The device, if the input voltage from the first power source is supplied to the first converter circuit, sets the second output voltage to be higher than a currently set voltage and lower than 1/n of the input voltage. The device then performs control to supply the input voltage from the first power source to the first converter circuit.

What is claimed is: 
     
         1 . An electronic device comprising:
 a first voltage converter circuit that converts an input voltage from a first power source or a second power source to a first output voltage, the first output voltage being 1/n of the input voltage, where n is an integer greater than or equal to 2;   a second voltage converter circuit that converts the input voltage from the second power source to a second output voltage;   a third voltage converter circuit that converts a higher one of the first output voltage and the second output voltage to a third output voltage, and supplies the third output voltage to a load; and   one or more processors or circuits that cause the electronic device to function as:   a control unit that sets the second output voltage of the second voltage converter circuit,   wherein the second voltage converter circuit outputs the second output voltage set by the control unit,   wherein the control unit:
 in a case where the input voltage from the first power source is to be supplied to the first voltage converter circuit, sets the second output voltage to a first voltage that is higher than a currently set voltage and lower than 1/n of the input voltage from the first power source, and 
 after setting the second output voltage to the first voltage, performs control to supply the input voltage from the first power source to the first voltage converter circuit. 
   
     
     
         2 . The electronic device according to  claim 1 ,
 wherein the first power source is an external power source which can be connected to the electronic device and the second power source is a battery installed in the electronic device.   
     
     
         3 . The electronic device according to  claim 2 ,
 wherein the control unit performs a control such that the input voltage from the second power source is supplied to the first voltage converter circuit and the second voltage converter circuit in a case where the first power source is not connected to the electronic device, and the input voltage from the second power source is supplied to the second voltage converter circuit and the input voltage of the first voltage converter circuit is switched from the input voltage from the second power source to the input voltage from the first power source in a case where it is detected that the first power source is connected to the electronic device.   
     
     
         4 . The electronic device according to  claim 3 , wherein the one or more processors or circuits further causes the electronic device to function as:
 a switch provided between the second power source and the first voltage converter circuit,   wherein the input voltage from the second power source is supplied to the first voltage converter circuit in a case where the switch is on, and the input voltage from the second power source is not supplied to the first voltage converter circuit in a case where the switch is off, and   the control unit turns on the switch in a case where the first power source is not connected to the electronic device, and turns off the switch in a case where the first power source is connected to the electronic device.   
     
     
         5 . The electronic device according to  claim 2 , wherein
 the control unit performs control so that the second output voltage becomes a second voltage that is higher by a predetermined value than a lower limit value of an operable voltage range of the third voltage converter circuit in a case where the first power source is not connected to the electronic device, and   the control unit controls the second voltage converter circuit so that the second output voltage changes from the second voltage to the first voltage in a case where it is detected that the first power source is connected to the electronic device.   
     
     
         6 . The electronic device according to  claim 5 ,
 wherein the electronic device receives power from the first power source in a manner compliant with a USB Power Delivery standard, and   wherein the control unit requests a higher voltage that is higher than a voltage of the battery of fully charged, from the first power source in the case where it is detected that the first power source is connected to the electronic device.   
     
     
         7 . The electronic device according to  claim 6 ,
 wherein the control unit performs control so as to request the higher voltage from the first power source after the second output voltage becomes the first voltage.   
     
     
         8 . The electronic device according to  claim 7 ,
 wherein the first voltage is lower than 1/n of the input voltage from the first power source by a predetermined voltage.   
     
     
         9 . The electronic device according to  claim 1 ,
 wherein the first voltage converter circuit has a higher voltage conversion efficiency than the second voltage converter circuit.   
     
     
         10 . The electronic device according to  claim 9 ,
 wherein the first voltage converter circuit is a switched capacitor converter.   
     
     
         11 . The electronic device according to  claim 1 ,
 wherein the input voltage from the first power source is higher than the input voltage from the second power source.   
     
     
         12 . The electronic device according to  claim 1 ,
 wherein the control unit changes the second output voltage to the first voltage by gradually changing the setting of the second output voltage.   
     
     
         13 . The electronic device according to  claim 1 ,
 wherein the control unit controls the second voltage converter circuit so that a period of time in which the second output voltage changes from the currently set voltage to the first voltage is longer than a period of time from when the input voltage from the first power source is supplied to the first voltage converter circuit to when the first output voltage changes to 1/n of the input voltage from the first power source.   
     
     
         14 . A control method that is carried out by an electronic device that includes:
 a first voltage converter circuit that converts an input voltage from a first power source or a second power source to a first output voltage, the first output voltage being 1/n of the input voltage, where n is an integer greater than or equal to 2;   a second voltage converter circuit that converts the input voltage from the second power source to a second output voltage;   a third voltage converter circuit that converts a higher one of the first output voltage and the second output voltage to a third output voltage, and supplies the third output voltage to a load; and   the control method comprising:
 in a case where the input voltage from the first power source is to be supplied to the first voltage converter circuit, setting the second output voltage to a first voltage that is higher than a currently set voltage and lower than 1/n of the input voltage from the first power source, and 
 after setting the second output voltage to the first voltage, performing control to supply the input voltage from the first power source to the first voltage converter circuit. 
   
     
     
         15 . A non-transitory computer-readable medium that stores a program that causes, when executed by a computer included in an electronic device to perform a control method,
 wherein the electronic device includes:
 a first voltage converter circuit that converts an input voltage from a first power source or a second power source to a first output voltage, the first output voltage being 1/n of the input voltage, where n is an integer greater than or equal to 2; 
 a second voltage converter circuit that converts the input voltage from the second power source to a second output voltage; 
 a third voltage converter circuit that converts a higher one of the first output voltage and the second output voltage to a third output voltage, and supplies the third output voltage to a load; and 
   wherein the control method comprising:
 in a case where the input voltage from the first power source is to be supplied to the first voltage converter circuit, setting the second output voltage to a first voltage that is higher than a currently set voltage and lower than 1/n of the input voltage from the first power source, and 
 after setting the second output voltage to the first voltage, performing control to supply the input voltage from the first power source to the first voltage converter circuit.